-
Notifications
You must be signed in to change notification settings - Fork 0
/
casing.go
320 lines (291 loc) · 7.46 KB
/
casing.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
// Package casing helps convert between CamelCase, snake_case, and others. It
// includes an intelligent `Split` function to take almost any input and then
// convert it to any type of casing.
package casing
import (
"strconv"
"strings"
"unicode"
)
// Borrowed from Go lint (https://github.com/golang/lint)
var commonInitialisms = map[string]bool{
"ACL": true,
"API": true,
"ASCII": true,
"CPU": true,
"CSS": true,
"DNS": true,
"EOF": true,
"GUID": true,
"HTML": true,
"HTTP": true,
"HTTPS": true,
"ID": true,
"IP": true,
"JSON": true,
"LHS": true,
"QPS": true,
"RAM": true,
"RHS": true,
"RPC": true,
"SLA": true,
"SMTP": true,
"SQL": true,
"SSH": true,
"TCP": true,
"TLS": true,
"TTL": true,
"UDP": true,
"UI": true,
"UID": true,
"UUID": true,
"URI": true,
"URL": true,
"UTF8": true,
"VM": true,
"XML": true,
"XMPP": true,
"XSRF": true,
"XSS": true,
// Media initialisms
"1080P": true,
"2D": true,
"3D": true,
"4K": true,
"8K": true,
"AAC": true,
"AC3": true,
"CDN": true,
"DASH": true,
"DRM": true,
"DVR": true,
"EAC3": true,
"FPS": true,
"GOP": true,
"H264": true,
"H265": true,
"HD": true,
"HLS": true,
"MJPEG": true,
"MP2T": true,
"MP3": true,
"MP4": true,
"MPEG2": true,
"MPEG4": true,
"NTSC": true,
"PCM": true,
"RGB": true,
"RGBA": true,
"RTMP": true,
"RTP": true,
"SCTE": true,
"SCTE35": true,
"SMPTE": true,
"UPID": true,
"UPIDS": true,
"VOD": true,
"YUV420": true,
"YUV422": true,
"YUV444": true,
}
var commonSuffixes = map[string]bool{
// E.g. 2D, 3D
"D": true,
// E.g. 100GB
"GB": true,
// E.g. 4K, 8K
"K": true,
// E.g. 100KB
"KB": true,
// E.g. 64kbps
"KBPS": true,
// E.g. 100MB
"MB": true,
// E.g. 2500mbps
"MPBS": true,
// E.g. 1080P
"P": true,
// E.g. 100TB
"TB": true,
}
// TransformFunc is used to transform parts of a split string during joining.
type TransformFunc func(string) string
// Identity is the identity transformation function.
func Identity(part string) string {
return part
}
// Initialism converts common initialisms like ID and HTTP to uppercase.
func Initialism(part string) string {
if u := strings.ToUpper(part); commonInitialisms[u] {
return u
}
return part
}
// State machine for splitting.
const (
stateNone = 0
stateLower = 1
stateFirstUpper = 2
stateUpper = 3
stateSymbol = 4
)
// Split a value intelligently, taking into account different casing styles,
// numbers, symbols, etc.
//
// // Returns: ["HTTP", "Server", "2020"]
// casing.Split("HTTPServer_2020")
func Split(value string) []string {
results := []string{}
start := 0
state := stateNone
for i, c := range value {
// Regardless of state, these always break words. Handles kabob and snake
// casing, respectively.
if unicode.IsSpace(c) || unicode.IsPunct(c) {
if i-start > 0 {
results = append(results, value[start:i])
}
start = i + 1
state = stateNone
continue
}
switch {
case state != stateFirstUpper && state != stateUpper && unicode.IsUpper(c):
// Initial uppercase, might start a word, e.g. Camel
if start != i {
results = append(results, value[start:i])
start = i
}
state = stateFirstUpper
case state == stateFirstUpper && unicode.IsUpper(c):
// String of uppercase to be grouped, e.g. HTTP
state = stateUpper
case state != stateSymbol && !unicode.IsLetter(c):
// Anything -> non-letter
if start != i {
results = append(results, value[start:i])
start = i
}
state = stateSymbol
case state != stateLower && unicode.IsLower(c):
if state == stateUpper {
// Multi-character uppercase to lowercase. Last item in the uppercase
// is part of the lowercase string, e.g. HTTPServer.
if i > 0 && start != i-1 {
results = append(results, value[start:i-1])
start = i - 1
}
} else if state != stateFirstUpper {
// End of a non-uppercase or non-lowercase string. Ignore the first
// upper state as it's part of the same word.
if i > 0 && start != i {
results = append(results, value[start:i])
start = i
}
}
state = stateLower
}
}
// Include whatever is at the end of the string.
if start < len(value) {
results = append(results, value[start:])
}
return results
}
// Join will combine split parts back together with the given separator and
// optional transform functions.
func Join(parts []string, sep string, transform ...TransformFunc) string {
for i := 0; i < len(parts); i++ {
for _, t := range transform {
parts[i] = t(parts[i])
if parts[i] == "" {
// Transformer completely removed this part.
parts = append(parts[:i], parts[i+1:]...)
i--
}
}
}
return strings.Join(parts, sep)
}
// MergeNumbers will merge some number parts with their adjacent letter parts
// to support a smarter delimited join. For example, `h264` instead of `h_264`
// or `mp3-player` instead of `mp-3-player`. You can pass suffixes for right
// aligning certain items, e.g. `K` to get `MODE_4K` instead of `MODE4_K`. If
// no suffixes are passed, then a default set of common ones is used. Pass an
// empty string to disable the default.
func MergeNumbers(parts []string, suffixes ...string) []string {
// TODO: should we do this in-place instead?
results := make([]string, 0, len(parts))
prevNum := false
suffixLookup := map[string]bool{}
for _, word := range suffixes {
suffixLookup[strings.ToUpper(word)] = true
}
if len(suffixes) == 0 {
suffixLookup = commonSuffixes
}
for i := 0; i < len(parts); i++ {
part := parts[i]
if _, err := strconv.Atoi(part); err == nil {
// This part is a number!
// Special case: right aligned word
if i < len(parts)-1 && suffixLookup[strings.ToUpper(parts[i+1])] {
results = append(results, part+parts[i+1])
i++
continue
}
if !prevNum {
if i == 0 {
// First item must always append.
results = append(results, part)
} else {
// Concatenate the number to the previous non-number piece.
results[len(results)-1] += part
}
prevNum = true
continue
}
prevNum = true
} else {
// Special case: first part is a number, second part is not.
if i == 1 && prevNum {
results[0] += part
prevNum = false
continue
}
prevNum = false
}
results = append(results, part)
}
return results
}
// Camel returns a CamelCase version of the input. If no transformation
// functions are passed in, then strings.ToLower is used. This can be disabled
// by passing in the identity function.
func Camel(value string, transform ...TransformFunc) string {
if transform == nil {
transform = []TransformFunc{strings.ToLower}
}
t := append(transform, strings.Title)
return Join(Split(value), "", t...)
}
// LowerCamel returns a lowerCamelCase version of the input.
func LowerCamel(value string, transform ...TransformFunc) string {
runes := []rune(Camel(value, transform...))
runes[0] = unicode.ToLower(runes[0])
return string(runes)
}
// Snake returns a snake_case version of the input.
func Snake(value string, transform ...TransformFunc) string {
if transform == nil {
transform = []TransformFunc{strings.ToLower}
}
return Join(MergeNumbers(Split(value)), "_", transform...)
}
// Kebab returns a kabob-case version of the input.
func Kebab(value string, transform ...TransformFunc) string {
if transform == nil {
transform = []TransformFunc{strings.ToLower}
}
return Join(MergeNumbers(Split(value)), "-", transform...)
}